Spray the inside of the crockpot with non-stick cooking spray to prevent sticking.
Start by layering one-third of the potatoes on the bottom of the crockpot.
Sprinkle a layer of ham on top of the potatoes, followed by some of the chopped onion.
Pour about 1/3 of the soup mixture over the potato and ham layer, spreading it as evenly as possible.
Sprinkle 1/3 of the cheese mixture (both cheddar and mozzarella) over the soup.
Repeat this layering process (potatoes, ham, onions, soup mixture, and cheese) two more times until all ingredients are used. Make sure the top layer is cheese to achieve a delicious golden top layer when done.
Step 4: Cook in the Crockpot
Cover the crockpot with the lid and set it to cook on low for 6-7 hours or high for 3-4 hours. Cooking times may vary based on your crockpot model, so check the tenderness of the potatoes by poking them with a fork.
When the potatoes are fork-tender and the cheese is bubbly and melted, it’s ready.
Step 5: Serve and Garnish
Let the casserole rest for about 5 minutes, so the sauce thickens slightly before serving.
Garnish with freshly chopped parsley or chives, if desired, for a pop of color and flavor.
